We search for CP violation in Cabibbo-suppressed charged D meson decays by measuring the difference between the CP-violating asymmetries for the Cabibbo-suppressed decays D-+/- -> K+K-pi(+/-) and the Cabibbo-favored decays D1/s -> K+K-pi(+/-) in the K+K- mass region of the phi resonance. Using 955 fb(-1) of data collected with the Belle detector, we obtain A(CP)(D+->phi pi+) (+0.51 +/- 0.28 +/- 0.05)%. The measurement improves the sensitivity of previous searches by more than a factor of 5. We find no evidence for direct CP violation.